The effect of zinc deficiency on alkaline phosphatase in pulp and odontoblast will be studied. Weanling (Sprague-Dawley) rats 30 dayd old, weighing 75 g will be divided into 3 groups, zinc deficient (minus Zn), pair-fed control (plus ZnP) and ad libitum control (plus ZnA). They will be fed MIT 200 diet with or without zinc supplementation for 35 days. At the end of the experiment, rats will be sacrificed by decapitation and pulps and odontoblasts from maxillary and mandibular incisors will be dissected. Body weight, serum zinc and serum AP will be measured weekly. AP in odontoblasts, pulp, and ramus will be measured after tissues are homogenized.